. >> my question, have you ever heard of campbell's law? >> no. >> pardon me, i would again. the greater the social, economic consequences of say with the statistics such as test scores, the more likely it is that the statistic itself will become corrupted. and that is corrupting the social processing it is intended to monitor spend time writing a short piece for "the wall street journal" to summarize some of the key findings. one of the headlines is smart managers will use statistics to evaluate employees, smart and playful figure how to manipulate those statistics. the one that is quite scary in the book from new york states where they simply decide that they would provide data on mortality rates or angioplasty, for cardiology. information is always good, it turned out that the new times are somewhat followed up and the high proportion, something like 78% of cardiologists have it delivered a change their behavior because of the evaluation. it was not to kill fewer people, it wasn't like boy, i killed a lot of history. today i'm not going to drink, right? [laughter] it was o